The homologation of low-flatcar wagons: instrumentation and on-track tests

Low-flatcar wagons are designed to load entire articulated lorries instead of loading only the containers in order to make the loading and unloading stages easier and faster. This design implies a particular layout of the bogie and suspension system, aiming at minimizing the height of the flatcar with respect to the rail level. This solution influences the dynamic behavior of the wagons, reducing the steering capability and causing high lateral forces on the driving wheels when low-radius curves or turnouts are negotiated. Aim of the work is the homologation of low-flatcar wagons on the Italian railways. Besides the classical homologation procedure prescribed by the EN14363 rule, a particular focus will be devoted to the running safety when negotiating turnouts. Indeed, it will be demonstrated that, under certain conditions, this is a very critical running condition for these vehicles. First, a numerical analysis is performed to identify the most critical condition. Then, this condition is reproduced experimentally, measuring the wheel-rail contact forces in order to assess the running safety of these wagons.